The relationship between the Soviet Union and Poland was tenuous at best during World War II for a variety of reasons, and became more so, after the 1940 Katyn massacre of over 20,000 Polish servicemen by the Russians came to light. However, pragmatic general Władysław Sikorski was still open to some form of normalisation of Polish-Soviet relations, while general Władysław Anders was vehemently opposed. To boost morale, Sikorski began a tour of inspection of the Polish forces stationed in the Middle East in May 1943, tending to political affairs where necessary.
On 4 July 1943, while Sikorski was returning to London from an inspection of Polish forces deployed in the Middle East, his aircraft, a Royal Air Force Consolidated B-24 Liberator, serial number AL523, operated by No. 511 Squadron RAF, crashed into the sea 16 seconds after taking off from Gibraltar Airport at 23:07 hours.
The Liberator II was an LB-30 model built as an unarmed transport and operated by No. 511 Squadron of RAF Transport Command on long range flights between the UK and Gibraltar.
In 1972, the pilot, Flight Lieutenant Eduard Prchal, described the events: "I received the green light from the tower and we began our take-off run. I pulled the stick back and the aircraft started to climb. When I was at 150ft I pushed the controls of the aircraft forward to gain speed. Suddenly I discovered I was not able to pull the stick back. The steering mechanism was jammed or locked." The aircraft then lost height rapidly. Prchal closed the four throttles and warned the others through the intercom "Attention, crash". The aircraft crashed into the sea.
Sikorski, his daughter, Tadeusz Klimecki (his Chief of Staff), and eight other passengers were killed. While the official death toll included 11 fatalities, the exact number of passengers was not known. Of the six crew members on board, only Prchal survived.
The only survivor of the accident was the pilot Flight Lieutenant Eduard Prchal, one of six crew on the aircraft. The 11 passengers killed were:Colonel Victor Cazalet MC – Conservative Party Member of Parliament for Chippenham, British liaison officer to the Polish forces
Jan Gralewski – an Armia Krajowa courier
Major General Tadeusz Klimecki – Polish Army Chief of General Staff
Adam Kułakowski – Sikorski's adjutant
Zofia Leśniowska – Sikorski's daughter and secretary
Walter Heathcote Lock – Ministry of Transport representative in the Persian Gulf.
Colonel Andrzej Marecki – Polish Army Chief of Operations
Warrant Telegraphist Harry Pinder, Royal Navy – Chief of the Royal Navy signals station in Alexandria
Lieutenant Józef Ponikiewski, Polish Navy who was Sikorski's adjutant
General Władysław Sikorski – commander-in-chief of the Polish Army and Prime Minister of the Polish government in exile
Brigadier John Percival Whiteley OBE – Conservative Party Member of Parliament for Buckingham
Sikorski's body was collected by the Polish Navy destroyer ORP Orkan and transported to Britain. He was subsequently buried in a brick-lined grave at the Polish War Cemetery in Newark-on-Trent, England, on 16 July that year. Winston Churchill delivered a eulogy at his funeral. The bodies of Sikorski's daughter and four other passengers and crew were not found.
Sikorski's death marked a turning point for Polish influence amongst the Anglo-American allies. He had been the most prestigious leader of the Polish exiles and it was a severe setback for the Polish cause, for no Pole after him would have much sway with the Allied politicians.
A British Court of Inquiry convened on 7 July 1943 to investigate the crash, following the order by Air Marshal Sir John Slessor of 5 July 1943. On 25 July 1943 the Court concluded that the accident was caused by the "jamming of elevator controls" which led to the aircraft being uncontrollable after take-off. The report noted that "it has not been possible to determine how the jamming occurred" although it ruled out sabotage. Slessor was not satisfied with the report and on 28 July ordered the Court to continue its investigation to find out whether the controls were indeed jammed or not, and if they were, then for what reason. Despite further investigation the Court was unable to resolve Slessor's doubts. The Polish government refused to endorse this report because of the contradictions cited therein, and the lack of conclusive findings.
a) Liberator AL 523, total all up weight 54,608 lbs, took off from Gibraltar at 23.07 hours on the 4th July 1943 bound for U.K. The weather was fine, wind light, no cloud, visibility 10 miles. The aircraft was airborne after a run of approximately 1100 yards, climbed to about 150 feet in a perfectly normal manner and then gradually lost height, striking the sea on an even keel approximately 1200 yards after leaving the ground. The evidence suggests that the pilot had throttled back a moment before impact and that his engines had been running normally up to that time. The pilot was recovered by the Station rescue dinghy within six minutes of the crash and was the sole survivor.
b) The cause of the accident was, in the opinion of the Court, due to the aircraft becoming uncontrollable for reasons which cannot be established. The pilot, having eased the control column forward to build up speed after take-off, found that he was unable to move it back at all, the elevator controls being virtually jammed somewhere in the system. It is impossible, from the evidence available and examination of the wreckage, to offer any concrete reason as to why the elevator system should have become jammed."
"... The findings of the Court and the observations of the officers whose duty it is to review and comment on those findings have been considered and it is apparent that the accident was due to the jamming of the elevator controls shortly after take-off with the result that the aircraft became uncontrollable.
After most careful examination of all the available evidence, including that of the pilot, it has not been possible to determine how the jamming occurred but it has been established that there was no sabotage.
It is also clear that the captain of the aircraft who is a pilot of great experience and exceptional ability was in no way to blame.
The political context of the event, coupled with a variety of curious circumstances, immediately gave rise to speculation that Sikorski's death had not been an accident, and might have been the direct result of a Soviet, British, or even Polish conspiracy. Some modern sources still note that the accident was not fully explained; for example Jerzy Jan Lerski in his Historical Dictionary of Poland (1996), entry on the "Gibraltar, Catastrophe of", noted that "there are several theories explaining the event, but the mystery was never fully solved." However, as Roman Wapiński noted in his biographical entry on Sikorski in the Polish Biographical Dictionary in 1997, no conclusive evidence of any wrongdoing had been found, and Sikorski's official cause of death was listed as an accident.
In 2008, Sikorski was exhumed and his remains were examined by Polish scientists, who concluded in 2009 that he died of injuries consistent with an air crash, and that there was no evidence that Sikorski was murdered, thus ruling out theories that he was shot or strangled before the incident. However, they did not rule out the possibility of sabotage, which is still being investigated by the Polish Institute of National Remembrance. The investigation is ongoing as of 2012.
In 2012, Jerzy Zięborak revisited the evidence gathered by the Court of Inquiry in 1943 as well as other material that has been made available to date. His conclusion was that the accident resulted from the combination of factors. Firstly, the aircraft was overloaded and its centre of gravity was displaced beyond the permissible limit. Secondly, the aircraft speed at take-off was too low due to the excessive weight. Finally, the autopilot was switched on just after the take-off – contrary to the flight manual – and that caused an effect similar to the controls' jamming as seen by the second pilot. Evidence has been found that the surviving pilot Eduard Prchal did actually perform the second pilot's duties during the take-off, which he did not reveal at the time of the investigation. Jerzy Zięborak rejects General MacFarlane's opinion that Prchal's mental state during the take-off was the reason for the accident. He then compares Prchal's article written ten years after the accident with the relevant documents from the accident. It turns out that not only did Prchal write an untrue description of the accident, but he forgot some details he had earlier mentioned during his meetings with pilots. The differences included even the kinds of his own injury mentioned in the article and those reported in the medical examination after the accident. The author asks whether it was possible that Prchal had completely forgotten such details of the accident as for example the number of victims. The reason for these differences, i.e. whether Prchal lied deliberately in his article or suffered from a kind of partial amnesia as a result of his injury is not discussed. However, Jerzy Zięborak thinks that Prchal lied on purpose about the Mae West lifejacket.
Despite the deficiencies of the report, the results of the Court's investigations were finally accepted. The author concludes that this was a convenient solution for both the British and Polish government, as the details of VIPs' flight procedure could not be published in the Court's report during the war.